The 248 nm laser ablation of liquid benzene, chlorobenzene, toluene, benzyl chloride, and benzyl alcohol was investigated by photoacoustic, nanosecond photographic, and time-resolved spectroscopic measurements. Ablation threshold was confirmed to be correlated to photochemical reactivities of molecules, while no distinct relation between the threshold and boiling point of liquids was observed. Emissions from dissociated radicals responsible for the ablation were clearly detected at fluences highly above the threshold. On the basis of these results, it is strongly suggested that a photothermal mechanism dose not have an important role, and ablation is initiated by photochemical fragmentation.